1. Field of the Invention
The invention relates to computer systems and more particularly to controlling the width and/or frequency of communication links used in computer systems.
2. Description of the Related Art
Power consumption and associated performance and thermal issues are considerations for every computer system design. Many power saving techniques have been introduced to save power and mitigate the impact of thermal and battery power constraints. The frequency of operation (clock frequency) of the processor and its operating voltage can in large part determine its power consumption. Since power consumption and therefore heat generation are roughly proportional to the processor's frequency of operation, scaling down the processor's frequency has been a common method of staying within appropriate power limitations. Microprocessors utilized in mobile applications, i.e., those used in battery powered systems, are particularly sensitive to power considerations. That is in part due to the small, densely packed system construction that limits the ability of the mobile computer system to dissipate the heat generated by computer operation.
While power consumption issues are particularly important for portable computers, power consumption issues are important for all types of computers. For example, while battery life may not be a consideration for desktop computers, thermal considerations are still an important criteria. In particular, for desktop computers, the hotter they run, the more likely fans are turned on to try and cool the processor, which results in fan noise or frequent cycling of the fans, which may be objectionable to the computer user. In addition, saving power can have real economic benefits in terms of reduced electricity costs. Further, reduced power consumption and lower operating temperatures can improve system reliability. Reduced power consumption and lower operating temperatures can also allow for higher density server farms.
It would be advantageous to be able to control the width and frequency of communication links in a computer system both to provide power management capability as well as to provide flexibility in system design and configuration. It would be further desirable to be able to adjust width and frequency of communication links while the system remains in an operational state.